Allosaurus Vector ———————————————————————---- Control: D-> Roar 1 Lx1-> Call 1 Lx2-> Call 2 X-> Roar 2 —————————Description—————————— Allosaurus (/ˌæləˈsɔːrəs/) is an extinct genus of large theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic period (Kimmeridgian to late Tithonian ages). The name "Allosaurus" means "different lizard", alluding to its unique (at the time of its discovery) concave vertebrae. The first fossil remains that could definitively be ascribed to this genus were described in 1877 by Othniel Charles Marsh. The genus has a very complicated taxonomy and includes at least three valid species, the best known of which is A. fragilis. The bulk of Allosaurus remains have come from North America's Morrison Formation, with material also known from the Alcobaça Formation and Lourinhã Formation in Portugal with teeth known from Germany. It was known for over half of the 20th century as Antrodemus, but a study of the abundant remains from the Cleveland-Lloyd Dinosaur Quarry returned the name "Allosaurus" to prominence. As one of the first well-known theropod dinosaurs, it has long attracted attention outside of paleontological circles. Allosaurus was a large bipedal predator for its time. Its skull was light, robust, and equipped with dozens of sharp, serrated teeth. It averaged 8.5 meters (28 ft) in length for A. fragilis, with the largest specimens estimated as being 9.7 meters (32 ft) long. Relative to the large and powerful legs, its three-fingered hands were small and the body was balanced by a long, muscular tail. It is classified in the family Allosauridae. As the most abundant large predator of the Morrison Formation, Allosaurus was at the top of the food chain and probably preyed on large herbivorous dinosaurs such as ornithopods, stegosaurids, and sauropods. It is also possible that it hunted other predators. Scientists have debated whether Allosaurus had cooperative social behavior and hunted in packs or was a solitary predator that form congregations, with evidence supporting either side. In 1991, "Big Al" (MOR 693), a 95% complete, partially articulated specimen of Allosaurus was discovered, measuring about 8 metres (26 ft) long. MOR 693 was excavated near Shell, Wyoming, by a joint Museum of the Rockies and University of Wyoming Geological Museum team. This skeleton was discovered by a Swiss team, led by Kirby Siber. Chure and Loewen in 2020 identified the individual as a representative of the species A. jimmadseni. In 1996, the same team discovered a second Allosaurus, "Big Al II". This specimen, the best preserved skeleton of its kind to date, is also referred to A. jimmadseni. The completeness, preservation, and scientific importance of this skeleton gave "Big Al" its name. The individual itself was below the average size for Allosaurus fragilis, as it was a subadult estimated at only 87% grown. The specimen was described by Breithaupt in 1996. Nineteen of its bones were broken or showed signs of serious infection, which may have contributed to "Big Al's" death. Pathologic bones included five ribs, five vertebrae, and four bones of the feet. Several of its damaged bones showed signs of osteomyelitis, a severe bone infection. A particular problem for the living animal was infection and trauma to the right foot that probably affected movement and may have also predisposed the other foot to injury because of a change in gait. "Big Al" had an infection on the first phalanx on the third toe that was afflicted by an involucrum. The infection was long-lived, perhaps up to six months."Big Al II" is also known to have multiple injuries. ——————————Credits——————————— Earth Museum Scientists Jurassic Allosaurus Stegosaurus Rigko If Used, Credit Me. Music: Jurassic Park ———————————————————————
Credits to @Raptor_Saurus.
